This post hopes to assess the Blazers progress. We would expect a young team to improve and stats in general to get better. IMO one stat that is reliable is the point differential, just go to ESPN/NBA and notice
NBA point differential ….(same table is pasted below)
….All of the good teams win by a larger amount than the average teams. The bad teams, well OKC has a point differential of –9.4 which means on average they score 9.4 points less per game than their opponent.
Last year the Blazers were 41 & 41. Their point difference was-1.0 and suggested close to a 50/50 record, which is where we ended up. A point difference of -1 means for the year they scored 1 point less than their opponent each game. This year to date we are at +4.0 which should get us into the playoffs.
If we had a –1.0 this year that would probably place us around 10th in the western conference. So far we have improved an overall +5 when compared to last year – a significant improvement. However this post will only look at the improvement from the beginning of this year to the present.
Point differential after 29 games 2008 - all Teams
But the question is, ARE THE BLAZERS IMPROVING.
Below is a list of the first 29 games with an attempt to gauge their progress using point differential moving averages. I need to explain the three right columns in the table below. There are 2 moving averages and the season average. The "7 game diff" is the average point difference of the last seven games. Likewise the "21 game diff" is the average point difference of the last 21 games. And then of course the "Season" is a running average of the season.
Note: keep in mind, there is not truly a 7 game average until the seventh game, and not a 21 game average until the 21st game, e.g. at the end of game 9 the first 2 games drop off and we have an average of games 3 thru 9. You'll also notice at game 8 the 7 game average breaks away fron the other 2 averages. The same is true for the 21 game average, at game 22 the first game drops off and it (21 game average) breaks away from the season average..
Why do we use three moving averages. The "7 game" average is more sensitive than the "21 game" average, and the 21 game average is more sensitive than the season average. If a team is improving, the 7 game average should rise above the 21 game average and the 21 game average should rise above the season average. I hope this makes sense to those who are not used to moving averages. i.e. if we look at a 7 game span at the end of the year we should see better numbers.
Let me say it like this: with a team that’s getting better, if we compare the "7 game" average against the "21 game" average the 7 game average should be higher because the 21 game average will include earlier games when the team wasn’t as good.
Here are the raw numbers for PTB, a chart of these numbers is posted lower.
|Game||Team||Opponent||Us||Opp|| 7 game
But how do we gauge the stats when the strength of schedule fluctuates. I’ve plotted the moving averages below and included a " 7 game average difficulty" plot under the point differential plot.
The difficulty stat is a crude stat I created to gauge the toughness of the opponent. It also looks at the average toughness of the last seven games, so it should be viewed in comparison to the "7 game" point differential plot. It is based on what "jscot" and others have posted about our chance of winning when we play good teams at home, bad teams at home, good teams away, and bad teams away. And trust me, it is a very crude stat, but I was surprised how well it worked. This stat oscillates between one and zero, the closer to one the more difficult the schedule.
In reality the stat should never hit one or zero, but the first game was away against a good team and the stat was not yet a seven game average. After the first few games the only way to hit 1 again would be to play 7 games away, all against good teams.
At game 18 we beat Detroit and our seven game point differential rose to a hefty 16.9 but notice the strength of schedule was at a low point. Recently we have had our schedule get tough again and the point differential actually dipped below zero, and below the other two point diff averages. My take on this is that teams have seen the double team on Roy working and the Blazers will need to figure this out. The good news is that the 21 game average is still above the season average. If the 21 game average drops below the season average we would have to start asking some tough questions. Have the blazers peaked. Have other teams figured out the Blazers.
The 7 game point diff average will decline from time to time, but if we are a RISING and improving team it should spend more of its time above the other two averages.
I like the 7 game moving average, it allows you to have a bad game, but if overall you played well in the last 7 games it’s not going to move the 7 game average much. But if you’ve had a bad stretch (or long road series against good teams) it could dip below one or both of the other averages, but hopefully not for long.
If you would like to see this chart later in the year please let me know, actually it will be more telling later on.
Happy Holidays everyone, looks like I need to shovel the driveway again.
Please see reply to "upper left corners" 2nd comment concerning "white space" it’s helpful information on analyzing this chart. There are two comments, one is right below the other.